Spring driven guide bushing



s. S S .om mm a, B mu. A wm m mm v s s b Q s m Y Y wm mm E .mw mE b owmw E N A M all@ m Q D. Il. WILSON SPRING DRIVEN GUIDE BUSHIING FiledAug. 2, 1945 ATTORNEYS Feb. 6, 1945.

Patented Feb. 6, 1945 2,368,794 SPRING DRIvEN GUIDE BUSHING Delbert I.wilson, Dayton, ohio, assigner to The City Engineering Company, Dayton,Ohio, a corporation of Ohio` Application August 2, 1943, Serial No.497,016

12 Claims.

This invention relates to turning machines and particularly to screwmachines for high precision work.

An object of the invention is to provide a resilient driving connectionbetween the spindle of the screw machine and a support for the workpiece whereby vibration of the work piece relative to a cutting tool issubstantially eliminated.

Another object of thel invention is to provide a screw machine that -hasa driven work supporting collet that is connected to' the spindle of themachine by means of a` resilient driving connection whereby the colletwill rotate accurately on its axis of rotation for producing precisionwork. l

Another object of the invention is to provide a screw machine of thetype wherein the work rod is fed through a supporting collet -by meansof intermittent movement of the spindle of the screw machine foradvancing the work rod through the collet adjacent work tools forproducing turning operations wherein the work supporting collet isdriven by means of a spring that extends between the collet and thespindle of the screw machine to eliminate vibration Aof the collet.

Another object of the invention is to provide an apparatus foraccurately producing small work pieces in a highr speed turning machinethat is constructed and arranged in a manner that the support member forthe work'stock is driven at the same high speed of the work stock bymeans of a resilient connection between the work stock support memberand thev driving means for the same whereby all machine vibration iseliminated from the work stock supporting member to thereby produceprecision concentric turning operations, o

Another object of the invention is to provide a screw' machine of thetype thatI has a reciprocating spindle head for feeding work stockthrough a work support member for turning operations wherein the spindleof the machine drives'the work stock support member by means of a coiledspring that extends between the spindle and the work stock supportmember.

Further objects and advantages will become apparent from the drawing andthe following description.

In the drawing Figure Iis a longitudinal vertical cross-section of aportion of a screw machine mechanismincluding the spindle head and the.work stock support member, l f

Figure II is a vertical longitudinal cross-seclthe same.

spindle mounted within the spindle head is protion of a work stocksupport member and theA means fordriving the same that is constructed iny vided with the usual collet arrangement for engaging the work stock asit passes axially through the spindle so that the vwork `stock will befed thereby. In screw machines of this type it is preferable to have awork stock support member that is mounted adjacent the turning tools ofthe machine so Athat when the work stock is fed axially through the workstock support member thatk the work stock` will be held concentric with1 respect to the axis of ythe work stock support mechanismfor producingprecision turning op-` erations. The spindle head of the `machine isadapted to be reciprocated through a predetermined stroke as determinedby the length of the work piece that is being produced, and suitablemechanism can be provided for producingthis reciprocation inconventional manner.

In conventional practice it has been customary to rotate the `work stockwithin a work stock support member that was stationarily mounted so thatthe work stock was actually bearinged in the work stock support member.Also there has been provided live collet members for supporting the workstock whereby there was no relative movement between 'the work stock andthe support member, and also auxiliary bearinged devices wereprovidedfor supporting the work stock support member for rotationrelative to thestationary support. When using the live collets it hasbeen the conventional practice'to drivethe collet fromthe 4spindle ofthe screw machine through means of a rigid connection. o Suchconstructions have, however, produced inconsistent results in turningoperations because of the vibration and unbalance that was'producedbythe rotation of the driving member. o

In this invention there is providedv a resilient lcoiled spring disposedbetween the live collet and thespindle ofthe screw machine yfor drivingthe live collet. This resilient driving connection be-v tween thespindle and the livecollet breaks any solid driving connectiontherebetween so that any Vibration of the machine that would betransmitted through the spindle cannot be transmitted to the collet bythe driving connection. Also, the resilient spring provides meansWhereby the rotation of the collet is exceedingly well balanced, andwhat may be termed internal vibration of the collet is substantiallyeliminated, so that exceedingly small work can be turned with accurate.concentricity.

The theory. of :operationzlof the resilir'it:ifdriv-A -lo ing connectionbetweenthe spindle of the screw machine and the live collet has not beenthor-1. oughly understood, but it has been demonstrated upon screwmachines that the lresilie'ritflconnec#' y tion will permit moreaccurate...produ`ction,0h15.:

small pieces than when the .liveolleteis 'driven..

by conventional rigid driving connections. In fact, it has beendemonstrated thata live collet that was slightly oi balancecouldibeimadetorr accurately turn small diameter work pieceswvhen :z u);

the collet was driven by means of a spring rotating' atsthe same" highfspeed .asftlle'a'4A collet. 'y 'Iliem explanation `for `thisphenomenal'fresult'woul spring' is anI;exceedinglyexible'gmember :thatg5 each turn 'of -the/coil `springbalancesitsel'iwhnz operating athighfspeed4 and' as a resultthe spring' f unit' producesfa balancing offtheicolle'tithat it is driving Articlesfraslsmallffas 1.00191 inch: in.dil' ameter have f. beenaproducedf. on iscrewmachines 30 constructed iniaccordance-'.fwithi theiinventi'ongr: and-it is not unusuahtoproducefaturning opera tion on f work 'stock'thatLmayproduce:l anarti'cle of.0041inch1in diameteriuhavingaa 'lengthfioffasfmuch;'asiseveneeighthszzof an Linch'. ,t .Suchfthighlycollet-softhatzthe unexpected result in .thsdn ventiorry is the 'svbalancing-i effect-a that;therrotating-:1i spring has-.upon thetcollet..i

Asfillustratedf iniffthee drawingcthis: inventio as accurateturningzfoperations.; could not `lbet:` proef..` ducedif thereiwasitheislight'estmbration offth consistsof :a spindle-housing;Izfof-aascrewmass... chine-r that is adapted to .zfbecmounted upon-:rthe bediof'the''machiriezfor reciprocation'fthereupon f .1. in 'conventionalvmanners-:n Th'zhousingvl 0 carries a spindle .I.I that sis`driveilbyimsans .of a driving#v belt.' I2.A spindle l I of .the:screw'machinezimaysbezof :any conventional constri'ictionfionIhighgifsp eedi rota.

tion and that it is providedfWithi-.the usual colletlvtm or n chuck I 3that .f grips ftheziworle'stock-a: I 4 f for It is, of .i course;...understoodf that thev z driving; the. same .atithe speed ofzrotatron..of=.the spindle.; It -will also .beunderstood-ltliatatheucole 1et-or.chuck I3 isconstructedandarrangedainia e; manner. that when.-y.the.-..spindlel.-heads.I 0 is .ref '55 tracted, or reciprocated-.imarightwardidirection...

cantake-.a new. grip upon-.thework stockI.4 .for

another ladvancing-istrole .fwhenthe spindlelheadwo I is again.movedinla forwa1'd.directionf....

A stationary. supportv member...|5.is iprovided.r

/ forward of.rthespindleehead-I0Landfcarriesa work .stock support.member -20s Thestationary.,

support ,member ,.'I securedlto ,theLbed -of .the...(i-' screw Amachinev .ingany conventionalgmanner sothat thel spindlehead.. fl) willbe`recip1iocated.to-,f.

, Ward and away irom thesupport'membe'r I5 'dure ing normal operation ofthe"screw .'I11al':hine.pf.,v

The support member I5 alsocarri e`s itheftooho support "memberd' 'thatis AfproVide'dvvithturna` ingv tools "1,1 i' for producing turning"yoperations port member consists of a cylindrical housing 2| that has acylindrical body 22 extending through an opening in the support memberI5, a flange 23 on the body 22 being secured to the support member I5 bymeans of bolts 24. The body 22 ofthe support member 20 has an internalbore 25 that is adapted toreceive a. pairI of ball bearing members `26and 21 that are spaced ,bymeansof apairu of sleeves 21B.

Thzball bearingmembe'rs 'supporta rotatable sleeve 29r that has a pairof keys 30 extending toward the axis thereof to engage a colleti'3l thatis disposed within the interior of the sleeve 28;?f'f The' frontend ofthe sleeve 29 is provided ,withaa taperedtwallSZethat receives the taperon thecollet...3Iylwhilethe rear end of the sleeve29.."isprovidedewithea threaded portion 33 that threadedly receives aring member 34.

TlieI:ring-memberv 34 has the forward end thereoffiniengagement with thebearing member 21 to draw the shoulder 35 on the sleeve 29 againstfthe.. fo'rward'."abe'arinig -anem-bei'rfZB @andthereby"accurately'holdthefsleve #29*ldetweenthe' bearing members 26 and21. The` ring vmember-@Mis provid'ed'withan ex The; sleeve'f311surroundsnionetzend.offra coiled `1 spring 4I that has one endthereof engaging-anl f:

inwardly .extending'annular flangef42'provided on the extremeendg-thereof.` positionednla slotor holle44in-.the`.chuck I3.'-.fIt Willbe notedfthatthev springr4I Vis offsuch a diameterfthatfit closely tstheinternaLdiameter of vfthe. sleeve231 and. the opv posite .end of.the-spring onfzthefchuckf-:I is cfa diameter-that closelyitsthefchuckwhereby. vibra-A tionioi .-the.-springza-t.thezendsfthereotwill beheld to aminimum.

The.col1et.3 |`.is provided-.withfkey ways inthe body.,thereofto receivethe keysS extendingfromf. the .sleeve` 29 and .hastheythreaded.endthereoi engaged by the internally-threadedsleeve portion.ofthe.ring,member.f46. -A flatBelville spring 41 `i's positionedIbetweenthe ring .46 andthe ring 34 wherebythe' collet-,13| Will be.urged-in a right-V. warddirection by a predetermined force accorde v'ingftogthe adjustment. of thering.. 45 .upon the".--A collet `3|to.'compress.theBelvill spring..4,1'. '1A 1. locking sleeve 48 is'threadedwithinLthetsleeve to engage;.the' `encl df ..the;c.o1let.;3 ITand .hold.-the...

aforementioned adjustment whenobtaine Asilliistrated.ihiFigire II thereis 'illustrated a mo'died structure ofl a work "stock support .I `memberwherein a sleeve bearing is provided with-..

in which the work stock'lsupport memberrotates.

as driven. byl'a resi-lient.coiled spring fo-r" pro-`v ducing extremelyAaccurate 'turning operations.

In lthis" apparatus" theE workstock 'support inem;v

Aseillus'tratedeinFiure the?work-'toclefsupjq 'ber 5U is providedwith acylindrical bodyllil "have" The body is provided with an internalta-ipered bore 54 that receives an externally tapered bearing sleeve 55 thatmay be of the split sleeve type for adjusting the internal diameter ofthe bearing bore 56. The rear end of the tapered sleeve 55 is threadedto receive a nut 51 that engages a shoulder 58 provided in the body 5|to draw the tapered sleeve 55 within the tapered bore 54 in the body 5|.l

The bodyl 5| is provided with an internal recess 59 that receives a ballbearing 6D which provides a thrust bearing in a manner hereinafterreferred to. A rotating'sleeve 6| is positioned within the bearing bore56 of the bearing sleeve 55 and extends rearwardly therethrough toreceive an annular ring 62 that is threaded upon the threaded end 63 ofthe sleeve 6 A shoulder 64 is provided on the ring 62 to engage the ballbearing 60 whereby the rotating sleeve 6| may be drawn in a rightwarddirection to cause the flanged shoulder to engagethe forward end of thebearing sleeve 55 to thereby retain the rotating sleeve 6| accuratelybetween 'the split bearing sleeve 55 and the ball bearing 60. A setscrew 66 is provided in the ring 62 to hold the adjustment after it ,hasbeen obtained. l

The ring member 62 has an annular recess 61 that receives one end of acoiled spring 68, the extreme end 69 of the spring 68 extending into ahole in the bottom wall of the recess 61vwhereby the collet or chuck |3aof the spindle l Ha and is supported thereby. The en d 10 of the spring68 rests in a recess provided in the body of the chuck l3a whereby thespring 68 will be rotated with the spindle Ha. v

A sleeve 1| has the forward end thereof threaded and inserted into thethreaded wall 12 of the recess 61 whereby the sleeve 1| encloses aportion of the spring 68 to prevent the saine from whipping whenrotating atta high speed. i

The rotatable sleeve 6| has an internal bore 13 that receives the collet14, the rear end of the collet 14 beinglthreaded within a sleeve 15 thatslides within an internal bore 16 in the sleeve k6|.l

A spring 11 is positioned within the bore' 16 .between the sleeve andthe sleeve 6| to urge fthe collet 14 in a rightward directionwherebyvthe tapered head on the collet engages the tapered wall 18 inthe sleeve 6| to cause the collet to engage the work stock |4a extendingtherethrough with a predetermined force. Lubricating grooves 15,-arcprovided around the external surface of theretating sleeve 6| forproperly lubricating the bearing surface between it and the sleevebearing: 55.`

It is... of course, readihLun` the use of the bearing member'having theshorterV life when extreme' accuracy is desired. Referring to thestructure in Figure I, 4it will be seen that when'the `spindle isrotated by the drive belt l2 that thespring 4| will be driven y therebysince the end 44 of the spring `engages the collet or chuck i3. Drivingof the spring 4| by `means of the spindle Il causes the sleeve 31 tovbedriven by theopposite-end of the spring.

drive .the collet 3| through the keys 30,. The coil spring 4| provides acompletely resilient drive means between the spindlev and the collet 3|so that any axial vibration of the spindle or torsional vibration, willnot be transmitted to the collet 3| through the driving connection. Aspreviously described the spindle head llmoves toward-the work stocksupport member 20 when an article is to be produced by causing the workstock to move past the turning tool I1. Therefore, Vthe work stock i4will be moved axially through the collet 3| and since the Aspring 41provides a predetermined engaging force to be applied upon the workstock-I4 within the collet 3|, the work stock will be held accuratelyconcentrically within the work stock support member 2B. stock I4 isgripped by means of the collet 3|, but which permits axial slidingmovement of the work stock therein, Vwill prevent vibration of the workstock within the collet 3 f It will ybe apparent that the resilientdriving connection between the work stock support member and the spindleprovided .by the spring 4| will permit reciprocation of the spindlevhead I0 without in any way .aiecting the drive between the spindle andthe collet 3|. Thehigh speed of rotation of the spring 4| will absorbany vibration caused by ol balance of the elements that are connectedthereto and it apparently actslike a vflywheel to afbso-rb anddissipatethese vibra-` tions so that the element that is being driven bythe spring 4| will rotate accurately concentrically upon its axis.

The. functioning just described of the driving operation of the spring4| illustrated in Figure I- illustrated in Figure II. In Figure II thespring 68 drives the collet 14 carriedfin the sleevev6| through meansofthe ring 62that is secured to the sleeve 6|, the sleeve and the `colletrotating as a unit. In the latter instance, however, it will l be notedthat the sleeve .bearing provided by the bearing member 55 will, as isusual in all sleevek bearings, increase `thelaccuracy withwhichrthecollet i4 will be rotated. l v

In both structures disclosed in this invention the'thrust of the drivingsprings is taken by the l driving vsleeve that supports the collet sothat the sliding engagement between the collet and thelV andv that allsuch modifications as fall within the scope of the appended claims areintended to be included herein.

Having thus fully described roy-invention what Y This rotation of thesleeve 31 will in y Also, the force with` which the work` .E1 claim @asnewl anddesire tol secure 4byl vI ietters Patent is:

1'.' In ascrew. maohinefthe'coinbination of', a rotating spindle adaptedto engagework stock for` drivin-g same, a work stock support memberincludingt meansf'completely independent `ofsaid spindle forfrotatablysupporting the' work stock acoiled' spring meanspositionedA coaxiallyAbetween saidspindle andsaid rotatablemeans and connectedtheretowherebysaid rotatable means isdriven by said yspindle through said spring meansandlisbalanced byfsaid spring meansl to remove yvibrationl from saidrotatable means.

3f.' In a screw machine the combination of", a rotatablespindle adaptedto have work stock extend laxially therefrom, a'rotatable work stocksupportv `member independent of said spindle, means rotatably supportingsaid support member coaxially withl said spindle, said spindle beingmovable toward and away from said Workstock support member to feed workstock therethrough, and a resilient-driving connection between saidspindle and said rotatable means for driving the same' which consists ofa coiled spring positioned coaxially with said spindleand'said'rotatable means.

4; The combination of,a rotatable work stock- Ward saidfsupport memberduring operationy thereof for. movingwork stock therethrough concomitant'with performance of a work operation thereon, and a resilient drivingconnection coaxially arranged with respect to said spindle'and'- saidrotatable work stock supporting v,means for continuously driving thesupporting means during-all -movement of the `spindle which consists ofaf'compressible coiledspring.

5'; In a yscrewy machine thecombination of, aA

rotatable spindleadapted to have'work stock exyin drivingthezsarneftherefrom -irrespectivefof-'the position Jofreciprocation ofvsaid spindle relatively to saidtfsupport member.

'71. In ascrew` machinefthe combination of', a rotatable spindleadaptedto 'have work stockrextend 'axially therefrom, a stationarysupport memben `relatively towhich saidspindle isV reciprocable minedpressure, a coiled spring extending between y said spindle and saidrotatable'means for driving-'the same therefrom irrespective of theposi-v tion ofI reciprocation vof saidr spindle relativelytorsaidsupport member, and means to absorb thel Varying thrust ofsaid-'spring upon compression ofthe same caused byy reciprocation ofsaid spindl`e toprevent this thrust from being transmitted to saidvmeans for engaging the work stock.

8.` In a turning machine'the combination of; a

., stationary support member; *a rotatable spindle movable toward said'stationaryA support member' during.V a turning' operation to feed workstock carried Vthereby andV extending from the end thereofpast acutting" tool; a work stock support member 'independent' of saidvspindle for supporting work stock extending from said spindlecarriede'in said support and consisting tof,l bearing means carried bysaid support member, rotatable means supported by said lbearing meansand adapted to receive a collet `for supporting work` to have work stockextend axially therethrough that is:v fed axially by'y the spindleduring'a turn- Y ing operation. on the machine, a stationary'supportlmember'relatively to which said spindle is rreciprocabley means carriedbysaid" stationary tendaxi'all'y therefrom, a stationary supportmemberrelativelyto which saidl spindle is reciprocablefor advancing workstock carried therebyduring.. a.. turning operation on the machine, ro-

ber relatively to which said spindle is recipro- 'l cable forv advancingworkstock carried thereby duringy a turning operation. on. the machine,ro`v tatablezmeansrcarriedlby said member in coaxial alignment withysaid spindle-for supporting work stockt extending therefrom, meansVcarried byv said rotatable Vmeans for engaging work'y stock extendingtherethrough slidingly butwith. a predetervk mined pressure, and acoiled springfextendingbe tween' said-spindle and; said.7 rotatable:meansnfor support for' supporting work" stock that extends from saidspindle including means rotatably supporting'said workrstock-"supportmeans in said stationaryfsupport-coaxially with said spindle,v

and a ,circular coiled spring positioned'l coaxially between'g'saidspindle/.I and said rotatable means and drivinglyf interconnecting thesame to drive ther rotatable means and balance they 'same .toV

that is fed axially'by the spindle duringra turningl operationkon.-themaohine, a stationary sup portlmemberK relatively: to.y which saidspindle reciprocable, r means" 'carried" 4by said stationaryy support'for supporting workstockthat' extends from said spindleincluding'means'y rotatably sup-v portingfsaidmwork stock support meansinA said static-nary supportcoaxiallyf with' said spindle" Y consistingof 'a pairof" spaced ball bearing mem-` bers, anda kcircularcoiled'spring positioned coaxiallyf betweensaid' spindle yandsai'olrotatable` meansv and?" drivinglyr interconnecting the same to drive therotatable means and balance the same to eliminate vibration thereof.

11. In a screw machine the combination of, a spindle head including aspindle that is reciprocable with respect to the machine and is adaptedto have work stock extend axially therethrough that is fed axially bythe spindle during a turning operation on the machine, a stationarysupport member relatively to which said spindle is reciprocable, meanscarried by said stationary support for supporting work stock thatextends from said spindle including means rotatably supporting said workstock support means in said stationary support coaxially with saidspindle consisting of a sleeve bearing member, and a circular coiledspring positioned coaxially between said spindle and said rotatablemeans'and drivingly interconnecting the same to drive the rotatablemeans and ybalance the same to eliminate vibration thereof.v I

12. The combination of,`a stationary support member, means for slidablysupporting work stock, means rotatably supporting said means upon saidstationary support, spindle means adapted to have work stock extendtherefrom for support within said work stock support means a vandreciprocable with respect to said stationary support, coiled springmeans drivingly engaging said rotatable support means and said` spindlemeans and co-axial therewith whereby to drive said support means fromsaid spindle means, and

sleeve means extending from said rotatable means for partially enclosingsaid spring means to thereby prevent substantial axial deflection ofsaid spring means.

" DELBERT I. WILSON.

